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This Add-on allows the creation of 8-bit quantised PNGs which can
create much smaller (~75%) transparent PNGs than is capable
with the normal save for web exporter in Photoshop.

Technology

The Add-on has been created using the Adobe Common Extensibility Platform (CEP). Under the hood it uses the pngquant Library which can create 8-bit PNGs with alpha transparency at vastly smaller file sizes. It is based heavily on ImageAlpha which is a standalone mac app with similar functionality. This Add-on brings that functionality into Photoshop on both Mac and Windows.

Installation

Installation for CC 2014

Download the zip or clone the repository from Github.
Navigate to the build folder and locate the pngquantiser.zxp file.

Double click on the zxp file and Adobe Extension Manager should launch and allow you to install the Add-on. When asked "The publisher of the extension could not be verified... Are you sure you want to install this extension." Click Install.

Installation for CC 2015 and higher

As of CC 2015 Adobe has dropped support for Adobe Extension Manager in favour of installing via the Adobe Add-ons site. The Add-on can be installed from the Adobe Add-ons site here.

Manual installation for CC 2015 and higher

Download the zip or clone the repository from Github.
Navigate to the build folder and locate the pngquantiser.zxp file.

The easiest method is to download a third-party tool called ZXPInstaller and drag the zxp file onto the tool.

How it works

Once installed the Add-on can be found in the "Window" > "Extensions" menu under the entry "PNG Quantiser". Once the Add-on has been opened it can be docked in any pallete desired for future use.

  • Open an image in Photoshop that you would like to save as a quantised PNG.
  • Click on the "Load Current Image" button in the Add-on.
  • The image will now appear in the preview window in the Add-on.
  • The zoom level can be adjusted by clicking on the appropriate buttons above the preview window. It can also be adjusted using the mouse wheel and clicking on the image with the mouse.
  • The background colour of the preview window can be changed by clicking on the appropriate buttons below the preview window.
  • The number of colours to quantise the image by can be changed by clicking on the appropriate buttons below the preview window. The amount of file size being saved can be seen in the file size details area.
  • Once happy with the amount of compression the PNG file can be saved by clicking on the "Save Quantised Image" button.

Why not Donate?

If you find this Add on useful please think about
sending a donation to help fund the development.